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Patented May 26, 1931 UNITED STATES PATENT OFFICE HARRY T. BENNETT ATTDLE ROY G. STORY, OF TULSA, OKLAHOMA; S AID STORY AS- SIGNOR TO JOSIAHCHATFIELD, OF CLEVELAND, OHIO LUBRICATING OIL AND METHOD OF MAKING THESAME Io Drawing.

This, invention relates to lubricating oils and methods of making thesame, and more specifically to low pour point lubricating oils, whichare oils that will pour at the winter temperature where they are used,for example from about to about F. below zero.

One of the objects of the invention is to lower the pour point withoutimpairing the 10 lubricating properties of the oil.

Another object is to obtain andmaintain the low pour point. Inotherwords, this object is to roduce a lubricating oil having a stable, orxed, low pour point which is not 15 changed by exposure to the extremesof high and low atmospheric temperatures. This object maybe attainedeither by mixing the composition at a high temperature, or by theaddition of a stabilizer when the mixture is prepared at lowertemperatures, as will be hereafter described.

A further object is to produce a low pour point lubricating oil withoutcausing an objectionable change in the color of the oil.

A still further object is to accomplish these results by lowering thepour point without substantially changing the viscosity of the oil.

With the foregoing and. other objects in pended.

point by adding to a lubricating oil a quantity of-soap small enough toaccomplish this result without materially changing the viscosity of thelubricating oil. This quantity preferably ranges between five-hundredthspercent and three-tenths percent of the weight of the mass, and inactual practice we have found that one-tenth percent gives highlysatisfactory results. However, as will be hereafter pointed out, thereis a further problem involved in maintaining or stabilizing the low pourpoint. We have shown 'the operations require a relatively long time.

Application'filed October 24, 1927. Serial'No. 228,487.

how this can be accomplished by the use of relatively high temperaturesin the treatment of lubricating oils that will withstand suchtemperatures, and we have also shown how to accomplish this result bythe use of a stabilizer in the treatment of oils wnich will notwithstand the relatively high tem peratures.

In our early efforts to lower the pour point of a paraflin baselubricating oil, without changing its viscosity, we found that theaddition of very small percentages of soap, as heretofore mentioned,would produce the desired result for a more or less limited period. Forexample, we have prepared oils which showed pour points of -10 F. butafter exposure to weather temperatures ranging from 80 F. to 20 F., thepour point tended to rise and after long periods some oils even revertedto the original pour point of about 15 F. to 35 F. We discovered,however, that in those cases wherein the pour point was unstable, theoils had been prepared by mixing the soap in the oil at temperaturesbelow 300 F., whereas in every case in which the soap had been mixedwith the oil at temperatures in excess of 300 F. the pour point was verystable:

A temperature in excess of 300 F. for mixing the soap is suitable forsome oils, such as those of dark color and of rather viscous nature, butfor light colored lubricating oils and certain of those of relativelylow boiling points, it is desirable to maintain lower temperatures. Whenheating large volumes of oil to elevated temperatures, a darkening ofcolor'is often ex erienced due to oxidation Briefly stated, we prefer tolower the pour p also, expensive equipment is necessary and For thesereasons, it is evident that a method of making stable pour points forcertain oils, wherein high temperature is undesirable, would beadvantageous. Thus, ourprocess would become more flexible and broader inits application, if instead of limiting it to temperatures in excess of300 F. we could also carry out the process-at lower tempera- 'tures andat the same time produce an oil having a stable or fixed low pour point.This oil, an

we have accomplished in a simple, inexpensive and eficient manner.

For the preparation of low POllT'POlIlll 011s,

wherein loss of color causes no serious dam- 180 F. We have found highboiling alco-v hols and esters such as benzyl alcohol, cyclohexanol,glycerine and benzyl acetate are particularly suitable as stabilizingagents, even in such small quantities as 0.05 to 0.2 per cent.

Our method of mixing the soap with the oil depends on the temperature wemaintain. At temperatures from 300 to 350 F. we prefor to gradually addthe pure soap with the to violently agitate the mass until the mixtureis uniform. In this way a stable material is obtained.

At lower temperatures, for example, 150 to 180 F., in which instance astabilizing agent is necessary, we prefer to first prepare a soap jelland to then thoroughly mix the ell with the oil. This jell may beprepared y heating a small quantity of the oil to 300 to 350 F. andincorporating therein 3 to 10 percent b weight of the soap. This lattermethod a so produces a lubricating oil of stable pour point withoutheating the main body of oil to temperatures high enough to causesubstantial darkening in color.

Lubricating stocks from paraflin base crudes are derived from waxdistillate or namely that fraction of the crude coming from the stillafter the lower boiling oint products such as gasoline, naphtha, eroseneand gas oil have been removed by frac-f tional distillation. The yvaxdistillate is essentially a mixture of paraflin wax and lubricatingstock from which it is extremely diflicult to remove a sufiicient amountof wax to give a lubricant of pour point of 0 F.

In our rocess it is not necessary to remove all of t e wax-from theoil,'but only' the ma'or portion. .We treat the remaining oil an waxmlxture to producea stable low pour point product.

A clearer understanding of our invention may be obtained by a morespecific descrip- 50 to 100 F., is chilled until t tion of the wax hasseparated,"and the cold tion, of thedetails of one form of theinvention. I A wax distillate, having a pour point of e major pormixtureis forced under pressure through a filter to remove the separated wax.The

filtered oil or pressed distillate, having a our point of 20 to F. isthen separate by distillation into lubricating stocks of 90 to 1000seconds Saybolt at 100 F., depending on the grade of lubricant desired.The lubricating stock is then bleached, by any of the well known methodsof decolorization, such as the use of acid and clay, to the desiredcolor, and the resulting lubricating oil heated to 150 to 180 F.One-tenth per cent of aluminum stearate in the form of a jell, is thenthoroughly incorporated into the oil. After the oil and aluminumstearate are thoroughly mixed, one-tenth of one per cent of benzylalcohol, to act as a stabilizer, is dissolved in the mixture and themixture allowed to cool. The product has a pour point of 0 to -20 F. andis extremely stable to changing temperature conditions.

It is to be understood that we do not limit ourselves to the aboveexample. Other soaps as well as aluminum stearate, such as aluminumpalmitate, zinc stearate, zinc palmitate, etc., have given good resultsin amounts from five-hundredth of one percent to three- .tenths of onepercent. Also, the stabilizer mg from five-hundredths to two-tenths ofone percent may be used. As previously indicated, we wish it understoodthat temperatures other than those specified may be used, and that theoperation of stabilizing the pour point may be performed by mixing thesoap with the oil at a temperature higher than about 300 F., or by usinga suitable stabilizing agent when it is necessary ordesirable to employlower temperatures.

This application is a continuation in art of the application Serial No.98,380, ed March 29, 1926 jointly by Bennett, Story and Beckley andwhich related broadly to the use of minute quantities of soap foreffecting the reductiomin pour points of lubricating oils. This presentinvention provides for the treatment of crude petroleum to effect areduction in the pour point without afi'ecting the viscosity of the oil.

Claims for the addition of a soap to the oil while at a temperature of300 F.350 F.

are presented in our companion and divisional application Serial No.294,933, filed Department of Commerce Publicatiom-U. .S.

Government Master Specification for Lubrican'ts and Liquid Fuels andMethods for Sampling and Testing, on pages 40 and 41 of which is setforth Procedure for pourpoint.

We claim:

l. The method of making stable low pour pomt wax containing minerallubricating oils which comprises heating the oil to a temperature below300 F., mixing therein a quantity of soap sufficient to lower the pourpoint without materially chan ing the viscosity of the oil, andstabilizing t e mixture to maintain the low pour point by adding anorganic stabilizing agent selected from the group consisting of benzylalcohol, cyclo-hexanol, glycerine, and benzyl acetate.

1 2. The method of producing stable low pour point wax containin mineraloils, having stable pour points 0% 0 F. and lower, which comprisesheating the oil to a temperature below 300 F., mixing therein fivehundredths to three-tenths percent soap to lower the pour'point withoutmaterially afi'ecting the viscosity of the oil, and also mixingtherewith an organic stabilizing agent adapted to maintain the low pourpoint and selected from the group consisting of benzyl alcohol,cyclo-hexanol, glycerine, and benzyl acetate.

3. The method of makingstable low pour point wax containing minerallubricating oils which comprisesheating a lubricating -.oil compositionto 150 to 180 F., mixing therein five-hundredths to three-tenths percentsoap in the form of a jell and without materially affecting theviscosity of the oil, and dissolving therein five-hundredths totwo-tenths {er cent of an organic stabilizing agent selected from thegnoup consisting of benzyl alcohol, cyclo hexanol, glycerine, and benzylacetate.

4. The method of making stable low pour point wax containing minerallubricating oils which comprises heating a lubricating oil compositionto 150 to 180 F., mixing therein about one-tenth of one percent aluminumstearate in the form of a jell and without materially affecting theviscosity of the oil, and dissolving therein five hundredths totwotenths (percent of an organic stabilizing agent selecte from thegroupconsisting of benzyl alcohol, cyclo-hexanol, glycerine, and benzylacetate.

The method of making stable low pour pomt wax containing minerallubricating oils which comprises heating a lubricating 011 compositionto 150 to 180 F., mixing therein about one-tenth rcent aluminum stearatein the form of a ell, and dissolving therein about one-tenth percentbenzyl alcohol.

6. The methodof making a stable low pour pointwax containing minerallubricating oil whlch comprises removing a portion of the wax from theoil, treating the partially dewaxed product with soap to substantiallylower the pour point without materially aflecting the viscosity of theoil, and incorporating into the mixture an organic stabilizing agentselected from thegroup consisting of benzyl alcohol, cyclo-hexanol,glycerine, and benzyl acetate.

7. The method of making stable low pour point wax containing minerallubricating oils which comprises chilling wax distillate until the majorportion of the wax has crystallized, separating such portion of the waxnecessary to give a dewaxed distillate of pour point 20 to 35 F.,distilling said distillate to produce a lubricating stock having aviscosity of 90 to 1000 seconds Saybolt at 100 F., treating said stockto obtain the desired color, heating the resulting lubricating oil to150- to 180 F., and mlxing therein five-hundredths to three-tenthspercent soap in the form of a jell and without materially affecting theviscosity of the oil, and adding to said mixture five-hundredths totwo-tenths percent of an organic stabilizing agent selected from the.group consisting of benzyl alcohol, cyclo-hexanol,glycerine, and benzylacetate.

8. The method of making stable low pour point wax containing minerallubricating oils which comprises chilling wax distillate until the majorportion of the wax has crystallized, separating such portion of the waxnecessary to give a dewaxed distillate of pour point 15 to 35 F.,distilling said distillate to produce a lubricating stock having aviscosity of 90 to 1000 seconds Saybolt at 100 F., treating said stockto obtain the desired color, heating the resulting lubricating oil to150 to 180 F., and mixing therein fivehundredths to three-tenths percentsoap in the form of a jell, and adding to said mixture about one-tenthof one percent benzyl alcohol.

9. The method of making stable low pour point wax containin minerallubricating oils which comprises chi ling wax distillate until the majorportion of the wax has crystallized,

separating such portion of the wax necessary to give adewaxed distillateof pour point 15 to 35 F., distilling said distillate to produce alubricating stock having a viscosity .of 90 to 1000 seconds Saybolt atF.,

treating said stock to obtain the desired color, heating the resultinglubricating oil to 150 to 180 F., and mixing therein about onetenthpercent aluminum stearate in the form of a jell without materiallyafi'ecting the viscosity of the oil, and adding to said mixture,five-hundredths to two-tenths percent of an organic stabilizing agentselected from the group consisting of benzyl alcohol, cyclo hexanol,glycerine, and benzyl acetate. 10. The method of making stable low pourpoint wax containing mineral lubricating oils which comprises chillingwax distillate until the major portion of the wax has crystallized,separating such portion of the wax-necessary to give a dewaxeddistillate of pour point 15 to 35 F., distilling said distillate toproduce a lubricating stock having a viscosity of 90 to. 1000 secondsSaybolt at 100 F., treatin said stock to obtain the desired to 150 to180 F., and mixing therein about one-tenth percent aluminum stearate inthe form of a jell, and adding to said mixture gbifllt one-tenth of onepercent benzyl alco- 11. A stable low pour point wax-containinglubricating oil comprising a mineral lubrieating oil, a minute quantityof soap whereby from a group the low pour point is obtained, and astabilizer whereby said pour point is maintained,

the quantity of soap being small enough toproduce the low pour pointwithout materially changing the viscosity of the oil, and the stabilizerbeing less than two tenthspercent of the mass, said stabilizer beingselected consisting of benzyl alcohol, cyclo-hexano glycerine, andbenzyl acetate.

12. A stable low pour point lubricating oil comprising a minerallubricating oil, a soap whereby the low pour point is obtained, andbenzyl alcohol whereby said pour point is maintained, the soap beingfive-hundredths to three-tenths percent of the weight of the mass.

13. A stable low pour point wax-containin lubricating oil comprising amineral lu rictaing oil, a minute quantity of soap in proportlons notless than 0.05% nor more than 0.3% whereby a pour point is obtained.-lower than possessed by the same mineral lubricating oil without theaddition of said soap, and a stabilizer whereby said low pour point ismaintained, the quantity of v soap being sufliciently small to producethe low pour point without materially affecting the viscosit of the oil.

14. A lu ricating composition comprising a mineral lubricating oilhaving a relatively high pour point combined with aluminum stearatewhereby the pour oint of the oil is reduced to less than 20 1, theweight of the aluminum stearate being less than .3 percent of the weightof the mass.

15. A lubricating composition comprising a mineral lubricating oilhaving a relatively high pour point combined with aluminum stearatewhereby the pour oint of the oil is reduced to less than 20 the weightof the aluminum stearate, being about 0.1 percent of the weight of themass.

16. A lubricating composition comprising a mineral lubricating oilhaving a relatively high pour point and a viscosity of more thanSaybolt' at 100 F., combined with alumi num stearate whereby the pourpoint is reduced to about 0 F. without substantially affecting theviscosity of the oil, the weight of the aluminum stearate being about0.1 percent of the weight of the mass.

In testimony that we claim the foregoing we hereunto aflix oursignatures. HARRY T. BENNETT. LE ROY G. STORY.

